Hot & Cold Pack Therapy

When you have an injury, pain and swelling can prevent you from rehabilitating the affected body part. This can lead to weakening of the injured area and surrounding areas or limit range of motion. Using hot- and cold-pack therapies can help reduce pain and swelling as well as the time it takes to heal.

Science of Hot and Cold Packs

• Hot and cold packs are called puncture packs. When you bend them or hit them, the chemicals within the pack combine and generate either heat or cold.

  Cold packs utilize a chemical process called an endothermic reaction in which ammonium nitrate is dissolved in water and heat is absorbed.

  Hot packs use the opposite chemical process in which calcium chloride or magnesium sulfate is dissolved in water to produce an exothermic reaction.

  Puncture packs produce heat or cold for approximately 20 minutes.

Proper Use of Hot and Cold Packs

• When you experience an acute injury, chill the body area with a cold pack to help prevent swelling and reduce pain by numbing the area. Use cold frequently for the first three days, then begin heat-pack therapy. Heat increases blood circulation; starting it too soon may worsen swelling of the injured area by bringing more blood to it. After swelling is controlled with cold, use heat to loosen the muscles and tendons in the injury area to allow imrpoved range of motion. Do this prior to activity to improve the flow of blood, which brings oxygen and nutrients and removes wastes. Chill the same area after the activity to prevent more swelling.

Precautions

• While hot and cold packs are useful and convenient, be aware that they contain chemicals; if they leak, discontinue use and discard immediately. It is best to place them in a sealed plastic bag to prevent leakage. Hot and cold packs have a limited shelf life and should be discarded after the expiration date on the package. Never reuse a puncture pack and do not attempt to heat it in a microwave.